6 Reasons Why Your Furnace Keeps Turning Off and How to Repair It

Your furnace keeps your family warm during the frigid winter months, so it’s annoying when something isn’t quite right. One routine issue is a furnace that endlessly switches on and switches off again. This operating error is called short cycling. It strains your heating system and might lead to pricey repairs or even early breakdowns.

Short cycling can be the result of for a few reasons. Before you schedule furnace repair, read about the potential causes and how to resolve the problem.

1. Clogged Air Filter

The HVAC filter attracts airborne dust, hair and other debris that could cause problems for furnace. If you don’t replace the filter frequently, it can eventually be dirty and block the airflow. When this happens, a safety mechanism turns off the furnace to avoid overheating. Check the filter, and if it’s dirty, replace it. From now on, get a new filter every 30 to 90 days to prevent your furnace from short cycling.

2. Clogged Air Vents

A dirty filter isn’t the only issue that can reduce airflow and overheat your furnace. Walk around your house and check for closed or obstructed air vents. For adequate system balance and performance, keep all registers open, even in empty rooms.

3. Dirty Blower Wheel

The furnace blower consists of blades that move air through the ductwork. If they are covered in dirt, the air won’t travel properly, creating overheating and short cycling. Frequently replacing the filter is the simplest way to stop a dirty blower wheel. If the blades are already dirty, book furnace maintenance to have them cleaned.

4. Faulty Thermostat

Check your thermostat next. This is the cortex of your HVAC system and gives the furnace instructions on what to do. Ensure the thermostat is on heating mode and auto fan with the desired temperature shown on the screen. Try replacing the batteries. Also, check whether the thermostat is in bright sunlight or near a heat source that could affect the temperature reading. If you use a smart thermostat, visit the manufacturer’s site for troubleshooting instructions.

5. Dirty Flame Sensor

The flame sensor switches off the gas valve when no burner flame on. The sensor can’t sense the flame if it’s sooty, so the gas switches off prematurely and the furnace shuts off. Leave the adjustment of repairing a dirty flame sensor to a professional like Finch Air Conditioning & Heating.

6. Oversized Furnace

When it involves heating and cooling equipment, larger isn’t always best. A larger system warms up your house too rapidly, leading to uncomfortable temperature changes and short cycling. The only way to resolve this problem is to schedule new furnace installation.

If you try the solutions suggested here to no avail, it’s time to call in the professionals at Finch Air Conditioning & Heating. We’ll take a look at the situation, diagnose the cause, and do the necessary service. Our aim is to reintroduce indoor comfort, energy efficiency and dependable furnace performance for the rest of the season. And our repairs are supported by a 100% Satisfaction Guarantee for a year.* For more info about furnace short cycling, or to request HVAC repair, give us a call at 281-407-9478 right away!


*Not applicable to the Advantage Program. See your signed Advantage Program Agreement for full details and exclusions. 100% Satisfaction Guarantee is subject to certain restrictions and limitations as set forth in the applicable Terms and Conditions.